Neuronal Labeling in the Rat Brain and Spinal Cord from the Ovary Using Viral Transneuronal Tracing Technique

Abstract

In the present investigations the viral transneuronal labeling method, which is able to reveal hierarchial chains of central nervous system (CNS) neurons, was applied to identify sites in the CNS connected with the ovary and presumably involved in the control of ovarian functions. Pseudorabies virus was injected into the ovaries of rats and a few days later (at various times after the injection) the spinal cord and brain were examined for virus-infected neurons from the ovary. The virus-labeled nerve cells were identified by immunocytochemistry using polyclonal antiviral antibody. Virus-labeled neurons were detected both in the spinal cord and the brain. In the spinal cord such elements were observed in the intermediolateral cell column, in the dorsal horn close to the marginal zone and in the central autonomic nucleus. In the medulla oblongata and pons, neurons of several nuclei and cell groups (area postrema, nucleus of the solitary tract, dorsal vagal complex, nucleus ambiguus, paragigantocellular nucleus, parapyramidal nucleus, A1, A5 and A7 cell groups, caudal raphe nuclei, locus ceruleus, subceruleus nucleus, Barrington’s nucleus, Kölliker-Fuse nucleus) were found to be transneuronally labeled. In the mesencephalon, the ventrolateral part of the periaqueductal gray matter contained virus-labeled neurons. In the diencephalon, a very intensive cell body labeling was observed in the hypothalamic paraventricular nucleus and a few virus-infected neurons could be detected in the lateral and dorsal hypothalamus, in the arcuate nucleus, zona incerta, perifornical area and in the anterior hypothalamus. Concerning the telencephalic structures, virus-labeled cells were found in the bed nucleus of the stria terminalis and in the central amygdala nucleus. These findings provide the first neuromorphological evidence for the existence of a multisynaptic neuronal pathway between the ovary and the CNS, and give a detailed account of the structures involved in this pathway.

Effects of Thermal Stimulation, Applied to the Hindpaw via a Hot Water Bath, upon Ovarian Blood Flow in Anesthetized Nonpregnant Rats

“…Anatomical studies have demonstrated that the ovary receives sympathetic (splanchnic) and parasympathetic (vagal) efferent nerves in rats [15][16][17][18][19]. These autonomic nerves reach the ovary via ovarian plexus nerves (OPN) and superior ovarian nerves.…”

Cutaneous Mechanical Stimulation Regulates Ovarian Blood Flow via Activation of Spinal and Supraspinal Reflex Pathways in Anesthetized Rats

“…The present study showed that there are two types of reflex pathways, supraspinal and propriospinal, in the somato-ovarian vascular reflexes; whether the supraspinal or propriospinal pathway is activated depends on which cutaneous segment is stimulated. The reflex pathway from the hindpaw afferent, which enters the spinal cord at the level of L3-L5 [10], to the ovarian sympathetic nerve which emerges from the spinal cord mainly at T9-T10 [3], is a supraspinal pathway. There are at least five segments between this pair of afferent and efferent, which seem to be too far apart to take a spinal reflex pathway.…”

“…Supraspinal reflexes seem to be activated particularly when a limb afferent is stimulated, and segmental reflexes seem to be activated by stimulation of spinal segmental afferents entering the spinal cord at the level of thoracic and higher lumbar segments. In rats, the sympathetic nerve innervating the ovary emerges from the spinal cord mainly at the segments of T9 and T10 [3], while afferent inputs of the hindpaw enter the spinal cord at the level of L3-L5 [10]. This anatomical evidence suggests that the sympathetically-mediated reduction in ovarian blood flow during hindpaw stimulation takes supraspinal reflex pathways instead of segmental reflex pathways.…”

“…[The Japanese Journal of Physiology 55: [265][266][267][268][269][270][271][272][273][274][275][276][277]2005] The ovary is innervated by autonomic nerves in addition to being under the control of hormones (see review by Burden [1]). Histological studies in rats showed that the autonomic nerves innervating the ovary are sympathetic nerves and vagus nerves [2][3][4][5]. Recently, we demonstrated in anesthetized rats that stimulation of the sympathetic nerve that innervates the ovary causes a reduction in ovarian blood flow, while stimulation of the vagus efferent nerve that innervates the ovary had no effect on ovarian blood flow [6].…”

Effects of Electrical Stimulation of the Superior Ovarian Nerve and the Ovarian Plexus Nerve on the Ovarian Estradiol Secretion Rate in Rats

“…However, although several histological studies have described the innervation of vagal parasympathetic and sympathetic nerves including both afferents and efferents to the ovary, the roles of these autonomic nerves in ovarian function have not been sufficiently clarified [1][2][3][4][5][6]. Histological studies by Burden et al [1,7] demonstrated that autonomic nerves enter the ovary via hilar perivascular plexuses, and tiny branches from these plexuses extend into the contiguous steroidogenic interstitial gland cells.…”